1. Field of the Invention
The present invention relates to a terminal including an optical pointing device, and more particularly, to a click recognition method that can detect a click event using an optical pointing device, instead of using a separate button.
2. Description of Related Art
Generally, a portable device such as a cellular phone or a personal digital assistant (PDA) adopts a user interface using a keypad. The keypad included in the portal device consists of a plurality of direction buttons and buttons for inputting numbers and characters.
As a wireless Internet service such as a Wireless Broadband (WiBro) service and the like is currently being commercialized, the personal device also adopts an operating system (OS) that can support a graphical user interface (GUI) such as Window™ of Microsoft.
With the development in technologies, the portable device is using a pointing device such as a computer mouse. The technologies are disclosed in U.S. patent application Ser. Nos. 10/579,702 and 11/189,656.
Generally, a conventional optical pointing device used in the portable device may only move a pointer and a cursor. Therefore, a user may move the pointer or the cursor to a desired location using the optical pointing device and then “click” or “double click” a button that is displayed around or in a lower portion of the optical pointing device. Various types of buttons may be used such as a mechanical button or an electrical button.
However, for example, U.S. Pat. No. 7,313,255, registered on Dec. 25, 2007, discloses technology that can obtain similar results as a click through a vertical movement of a finger, i.e. a Z-axial movement, on an optical pointing device, instead of clicking a separate button.
Also, U.S. Pat. No. 7,313,255 discloses technology regarding “SYSTEM AND METHOD FOR OPTICALLY DETECTING A CLICK EVENT”. Here, the optical pointing device may recognize a finger motion from a finger movement on a sensing area The optical pointing device may receive a partial image of the finger in the sensing area, generate a plurality of image signals of the image, and detect a click motion of the finger from the plurality of image signals. In particularly, when a tracking quality obtained from the image signals decreases, the finger motion is determined as a finger lift-up motion. Conversely, when the tracking quality increases, the finger motion is determined as a finger put-down motion.
Also, in U.S. Pat. No. 7,313,255, when the put-down motion is detected after the finger lift-up motion is detected, it is determined whether a time interval between the finger lift-up motion and the finger put-down motion is within a predetermined time range, for example, within 0.1 through 0.3 seconds. When the time interval is within the time range, it may be regarded as a click event.
In this instance, the finger may simultaneously perform a vertical movement corresponding to a movement on the Z axis and a horizontal movement corresponding to a movement on the X-Y plane. An intent of the user who performs the above movements may be to relocate the finger on an image window and simultaneously move a cursor by deviating from an image sensing area (image input window of 2.2 mm by 2.2 mm) while moving a cursor, instead of generating a click event. For example, the above movement may frequently occur while scrolling. However, since the above application determines a click event based on only the vertical movement of the finger (the motion on the Z axis), a click event unintended by the user may occur even when the vertical movement and the horizontal movement are simultaneously performed. Specifically, according to a process defined in the above application, the finger motion for scrolling may not be discerned from the finger motion for the click event.